Interior Permanent Magnet Synchronous Motors (IPMSMs) have a stator and a rotor. As disclosed in Patent Document 1, for example, the rotor has a rotor core provided with magnet implantable holes arranged at regular intervals in the circumferential direction, and permanent magnets buried in the implantable holes. The stator has a stator core around which coils are wound at a plurality of portions. The electric current passing through the coils generates rotating magnetic fields, which cause the rotor and the stator to repeatedly attract and repel each other, and accordingly, the rotor rotates with respect to the stator.